﻿using System.Web.UI;
using System.IO;
using System.Web;

namespace SpeakOut.Lib.Web
{
    /// <summary>
    /// Got this code in a post from ScottGu. It deals with URL rewriting problems when doing
    /// post backs.
    /// </summary>
    public class FormRewriterControlAdapter : System.Web.UI.Adapters.ControlAdapter
    {
        protected override void Render(HtmlTextWriter writer)
        {
            base.Render(new RewriteFormHtmlTextWriter(writer));
        }
    }

    public class RewriteFormHtmlTextWriter : HtmlTextWriter
    {

        public RewriteFormHtmlTextWriter(HtmlTextWriter writer): base(writer)
        {
            InnerWriter = writer.InnerWriter;
        }

        public RewriteFormHtmlTextWriter(TextWriter writer): base(writer)
        {
            InnerWriter = writer;
        }

        public override void WriteAttribute(string name, string value, bool fEncode)
        {

            // If the attribute we are writing is the "action" attribute, and we are not on a sub-control, 
            // then replace the value to write with the raw URL of the request - which ensures that we'll
            // preserve the PathInfo value on postback scenarios
            if ((name == "action"))
            {
                HttpContext context = HttpContext.Current;

                if (context.Items["ActionAlreadyWritten"] == null)
                {

                    // Because we are using the UrlRewriting.net HttpModule, we will use the 
                    // Request.RawUrl property within ASP.NET to retrieve the origional URL
                    // before it was re-written.  You'll want to change the line of code below
                    // if you use a different URL rewriting implementation.
                    value = context.Request.RawUrl;

                    // Indicate that we've already rewritten the <form>'s action attribute to prevent
                    // us from rewriting a sub-control under the <form> control
                    context.Items["ActionAlreadyWritten"] = true;
                }
            }
            base.WriteAttribute(name, value, fEncode);
        }

    }
}
